HARADH, Yemen (Reuters) - Unfastening his grubby sling, Ali Yusef let out a gasp as his mangled forearm dropped limply to his side. Jumping out of a speeding pick-up truck to evade kidnappers last week, the young Ethiopian was lucky to get away with only a broken arm.
Yusef is one of thousands of Ethiopians lured by the promise of a better life in wealthy oil-rich Gulf Arab states who have found themselves trapped in a lawless and violent stretch of territory on the Yemeni side of the border with Saudi Arabia.
"It (jumping) was worth the risk," said Yusef, showing the blisters on his palms. "I'd rather die than let them catch me."
Plagued by sandstorms, drought, gun runners and drug smugglers, the 1,800-km (1,100-mile) strip of land along the Yemeni-Saudi border has long been a desolate, dangerous place.
But crumbling government control and a surge of migrants, driven out of the Horn of Africa by drought, poverty and persecution, have turned it into a kind of hell where criminal gangs roam freely, trading migrants like commodities.
Aid workers in Haradh, a smugglers' outpost on the border, say that the kidnapping of migrants for ransom is now common practice.
"Kidnap, robbery, sexual abuse, it's part of everyday life here," said Ali Al-Jafri, a logistics officer from the International Organization for Migration (IOM), which runs a camp in Haradh for 3,000 Ethiopians awaiting repatriation.
"It's become a business, an industry in itself."
Exploiting the chaos in the country after mass protests forced President Ali Abdullah Saleh to step down after 33 years in office, more than 103,000 men and women crossed the Red Sea into Yemen in 2011 - double the previous year's figure, according to the U.N. Refugee Agency (UNHCR).
The increased numbers are part of an exodus from the Horn of Africa that the UNHCR and IOM say represents one of the largest flows of economic refugees on earth.
"What you see in Yemen is just the tip of the iceberg," said Yacoub El Hillo, the director of the UNHCR's Bureau for the Middle East and North Africa.
"This is a lucrative business, it is a criminal business, and it is growing."
Chris Horwood, director of the Nairobi-based Mixed Migration Secretariat, said the kidnapping racket is already well established in the Sinai and more recently in eastern Sudan.
"We are calling it the ‘commoditization' of migrants," Horwood said.
"It is a lucrative, underground cash-cow. The proliferation of mobile phone networks and money transfer systems that so assist migrants to communicate and fund their journeys have become a curse used by criminals to extort what little the poorest have left."
About 75 percent of the migrants who come to Yemen are Ethiopians, most heading to wealthy Gulf Arab states, especially Saudi Arabia, in search of work.
Hussein Regin Suri, a stick-thin Ethiopian in flip-flops trudging along a coastal road toward the Saudi border, said he had left his wife, job and nine-month-old child behind in Addis Ababa.
"What I earn in two months teaching in Ethiopia, my brother makes in a week chopping vegetables in Riyadh," Suri said.
For most in Yemen - a country with the highest rate of chronic child malnutrition after Afghanistan - the migrants are a burden, another competitor in an already fierce scrap for limited resources.
Criminal gangs have scented opportunity, however. They snatch migrants from the roadside and detain and torture them to extract payment from their relatives abroad.
Nineteen-year-old Aisha Saeed Indris relates how her captors pressed lit cigarettes into her forearm to get her father's telephone number after they bought her from a Yemeni border patrol.
"They poured liniment in my eyes. Then they beat me all over my body with a metal chain," Indris told Reuters in a Haradh hospital where she was receiving treatment for her injuries.
"They took it in turns," she said, her voice faltering. "One of them held me down while the other raped me. Then they called my father in Ethiopia and told him that if he didn't wire them money, they'd shoot me."
It was only when a fellow migrant escaped and informed the police of her whereabouts that Indris was released.
LIKE FIGHTING AN INSURGENCY
Rattled by the flow of illegal immigrants, drugs and weapons, Saudi authorities have invested billions of dollars shoring up the border over the last decade.
Construction of a 75-km (45-mile) iron fence commenced in 2008. Floodlights, thermal cameras and electric wires have all made the crossing more perilous than before.
Sometimes, migrants say, Saudi border guards resort to brute force to repel those trying to sneak across the border into the kingdom in search of work.
The damp floor of a rundown hospital in Haradh is where many of those who attempt the journey end up. One man named Yusuf hoisted up yellow shorts to reveal a pair of bulging pink scars running up the backs of his thighs.
After shooting him in the legs, he said, Saudi patrolmen slung him in the back of a truck, drove him across the border and left him in a ditch under the baking sun. If not for a Yemeni farmer who found him and took him to the clinic, he would have died.
Yemeni officials are frustrated by the Saudi policy of ditching the would-be migrants they apprehend back across the border.
"The Saudis are a thousand times richer than us, they're supposed to build camps, repatriate them to their home countries," said Ibrahim Zaydaan, an official from Yemen's Ministry of Human Rights, who is tasked with documenting migrant abuse. "But instead they just shove them back over the border.
"It's like trying to dam a fast-moving river - in the short term you stop some water getting through, but eventually it's going to overflow."
A spokesman for the Saudi Interior Ministry said half a million people try to sneak into the country annually, and that border guards only open fire when they were fired upon.
"Our border security system is no different from other countries ... Those who arrive are sent back to where they came from," said the spokesman.
On Yemen's side of the border a climate of collusion and low political will to apprehend and prosecute smugglers is allowing the trade and abuse of migrants to flourish.
Ahmed, a military officer from Haradh who would only give his first name, is one of a handful of Yemeni security officials who have made a fortune helping smugglers move Africans into the world's top oil exporter.
In a country where more than 40 percent of the people live on less than two dollars a day, Ahmed's coordination with smugglers earns him around $20,000 a month.
Asked whether he runs into trouble moving migrants through government checkpoints, he laughed: "What checkpoints? This country is run by tribes not policemen: these people are my friends."
The Defense Ministry refuses to comment on the matter. But local authorities in Haradh say there is collusion between Yemeni border guards and smugglers but say they are overwhelmed, lacking both the authority and firepower to flush the smugglers out.
"Is there facilitation? Of course there's facilitation. I have no control over the border guards, they are under the Ministry of Defense," said Colonel Mohammed Ahmed Najd, Chief of Police for Haradh district.
"When we raid the smugglers' houses we face fierce resistance and shootouts. It's like fighting an insurgency," he said. "As long as these people keep arriving the smugglers will keep taking them. There is nothing we can do."
(Editing by Sami Aboudi and Sonya Hepinstall)